Distributed Dynamic Event-Triggered Control to Leader-Following Consensus of Nonlinear Multi-Agent Systems with Directed Graphs.

This paper investigates achieving leader-following consensus in a class of multi-agent systems with nonlinear dynamics. Initially, it introduces a dynamic event-triggered strategy designed to effectively alleviate the strain on the system's communication resources. Subsequently, a distributed control strategy is proposed and implemented in the nonlinear leader-follower system using the dynamic event-triggered mechanism, aiming to ensure synchronization across all nodes at an exponential convergence speed. Thirdly, the research shows that under the dynamic event-triggered strategy the minimum event interval of any two consecutive triggers guarantees the elimination of Zeno behavior. Lastly, the validity of the calculation results is verified by a simulation example.

[Non-carcinogenic Risk Assessment of Cadmium Exposure Through Drinking Water in Chinese Residents Based on Age-stratification Weight].

Drinking water is an important cadmium (Cd) exposure pathway for residents in China. In order to quantitatively characterize the risk of cadmium exposure through drinking water, the Cd concentrations of three main drinking water types in China were collected via systematic literature review. The probability distribution of the exposure parameters was estimated using regression models. The non-carcinogenic risk of cadmium exposure to residents through drinking water was evaluated by Monte Carlo simulation. The results showed that significant differences were found among Cd contents in the three water types. The geometric mean of ρ(Cd) in tap water, untreated underground water, and surface water were (0.48±0.78), (1.07±1.82), and (1.04±1.38) µg·L-1, respectively. The non-carcinogenic risk assessment showed that the median of hazard quotients in all age groups and in the three water types were found to be less than 1. Compared with the exposure dose threshold recommended by the US EPA, the probabilities exceeding the threshold of underground water, surface source water, and tap water were 2.4%, 1.3%, and 1.0%, respectively. Children aged 6-8 had the greatest daily average dose of Cd, and the least exposure dose was found in the 15-17 age group. The result of Monte Carlo simulation based on age-stratification weight showed that people 18-44 years old accounted for 50.8% of the total number of people who exceeded the exposure threshold. In summary, the probability of noncarcinogenic risk caused by Cd exposure through drinking water of Chinese residents was relatively low. However, people in some sub-groups still had a relatively high probability of exceeding the exposure dose threshold. It is necessary to further strengthen the control of cadmium pollution in drinking water in order to reduce the health risk caused by cadmium exposure and ensure drinking water safety.